Automatic switch



C. W. EISENMANN.

AUTOMATIC SWITCH.

APPLICATION FILED JUNE 16. 1916- 1,348,098. Patent d July 27, 1920.

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- ing the battery current.

CARI: W. EISENMANN, OF NEBRASKA CITY, NEBRASKA.

AUTOMATIC SWITCH.

Specification of Letters Patent.

Patented July 27,1920.

Application filed June 18, 1916. Serial No. 108,998.

To all whom it may concern:

Be it known that I, CARL W. EISENMANN, a subject of the Em eror of Germany, residin in Nebraska ty, Otoe county, State of ebrask'a, have invented Automatic Switches, of which the following is a specification.

One object of my invention is to provide a novel form of switch for automatically governing the connection of a generator to a storage batter that will open and-close at more nearly t e battery voltage than has heretofore been possible, and at the same time maintain this adjustment regardless of the voltage of the battery. This, besides reducing sparking at the contacts, renders it practlcable to use the same switch, without readjustment, on systems of differentvoltage, and also if the battery should become discharged down to the voltage of a single cell, this switch would close Within a fraction of a volt of, instead of at many times that voltage.

It is further desired toprovide an automatic switch whose parts shall be so arranged and connected to a storage battery and a generator that a small current shall be always supplied from the battery to said generator for exciting its field, thereby maintaining a circuit through the commutator and brushes of said generator practically regardless of any insulating material which may accumulate thereon, with a view to insuring that the generator shall produce current at the proper time after it is set in motion.

The invention also contemplates novel means for causing ener ization of. one or more of the windings o the switch with a relatively small current under certain conditions and with a larger current under other conditions, with a view to economiz- These objects and other advantageous ends I secure as hereinafter set forth, reference being had to the accompanying drawin s, in which,

igure 1 is a/diagrammatic view of an automatic switch constructed according to my invention, illustrating the connections betiween it and its associated apparatus; an

Fig. 2 is a diagrammatic view illustrating a special form of my invention.

In the above drawings 1 represents a store e battery and 2 a suitable generator for c ar in the same; the negative terminals of ot battery and generator bein ermanently connected. The preferre orm of automatic controlling switch constituting my invention consists. of two U- shaped cores 3 and 4 having their pole pieces adjacent each other but spaced apart for the reception of an armature 5 polarlzed in any suitable manner. In the case illustrated said armature is formed as a permanent magnet and is pivotally supported in any suitable manner on a pin or s indle 6 at its lower end while its upper end carries a contact 7 placed to coact with a fixed contact 8 when said armature has been drawn as near as possible toward the pole pieces of the oore4.

The positive terminal of the storage battery is directly connected to the main movable switch contact 7 and is likewise connected to one terminal of a coil 9 wound on the core 3, there being an electric valve or rectifier 10 connected in circuit with the coil 9 in such manner as to permit a maximum How of current in the direction indicated by the arrow and a minimum current flow in the opposite direction.

Other means such as resistance material having a high temperature coefficient may be employed without departing from this invention.

The coil 9 is connected in series with a second coil 11 mounted. on the core 4: and connected through a coil 12 to the positive terminal of the generator 2. This second terminal of the coil 11 is likewise connected to the fixed switch contact 8. There is thus a flow of current from the positive terminal of the storage battery through the valve or other current governing device 10 and coils 9, 11 and 12, through the generator 2 to the negative terminal of said battery, but said coils are so wound that as long as the battery voltage is greater than that of the generator, the polarized armature 5 is repelled from the poles of the core 4 and attracted to the poles of the core 3.

When the voltage of the generator rises above that of-said battery, current flows from the former through the coils so that the operation of the valve 10. When the switch is'closed the coil 12 acts to attract the armature so as to hold the switch closed and the coils 9 and 11 are deenergized.-

,Current continues to be delivered to the battery untiLthe voltage of the generator falls. to such a point'as toreverse the current flow in the coil 12 and open the switch whereupon the coil 12 becomes deenergized except for the small current through the coils 9 and 11 and the coil 9 again attracts the armature 5 and the coil 11 repels it, causing the switch 7-8 to remain open and prevent further charging.

Thereafter while suflioient current flows through the electric valve 10 and the coils to maintain the armature 5 with the movable switch blade in its open position, this flow is relatively small because of the action of said valve, which may have any of'the forms well known to the art or which may take the form of a body of resistance having a sufiiciently high temperature co-efiicient to accomplish similar results. It will thus be seen that the two coils act together to cause movement of the armature in 'closing the switch and that the main charging current from the generator is operative in holding the armature with the movable switch contact in this closed Position, since it flows through the coil 12. his same coil however, acts to repel the armature from the pole piece of the core4 when the battery voltage becomes higher than that of the enerator and the current flow reverses, w ile the coils 9 and 11 thereafter act to respectively attract and repel said armature and hold it in its open position.

From the foregoing description, it will be noted that the switch opens and closes with a minimum difference between the voltages of battery and generator because at the time of opening the coil 12 is not opposed by any other agency.

In Fig. 2 have shown the parts arranged as in Fig. 1 except that the electric valve or other current limitin device 10 is connected between one termina of the coil 9 and .the positive terminal of a battery cellother than that constituting the positive terminal of the battery. With such connection the coils 9 and 11 are not deenergized when the switch case. a

I claim 1. The combination of a storage battery; a generator for charging the same; a switch for controlling the connection of the generator and battery; and operating means for said switch consistlngof a coil in series with the generator and switch for holding the latter closed when the battery is chargin and two other coils independent of sai switch and in series with said first coil acting to maintain the switch open when the battery voltage is higher than that of the generator.

2. The combination of a storage battery; a generator for charging the same; a switch for controlling the connection of the generator and battery; and operating means for said switch consisting of three coils in series between one terminal of the generator and the battery terminal of like polarity, said switch being connected in series with one of said coils and shunting the other two.

3. The combination of a storage battery; a generator for charging thesame; a switch for controlling the connection of the generator and battery; and operating means for said switch consisting of a coil in series with the generator and switch for holding the latter closed when the battery is charging and two other coils independent of said switch and in series with said first coil acting to maintain the switch open when the' battery voltage is higher than that of the generator, one of said latter coils being wound to attract and the other to simultaneously repel the movable element of the switch.

4. The combination of a storage battery; a generator forcharging the same; a switch for controlling the connection of said generator and battery; and oferating means for said switch conslsting 0 two coils permanently in circuit between one terminal of the battery and the generator terminal of like polarity and acting to cause closure of the switch when the voltage of the generator rises above that of the battery; with a third coil connected to be energized by the charging current from the generator to the battery and in series with said first two coils.

CARL w. EISENMANN.

'7-8 is closed-as would otherwise be the lit 

